JPH0441023B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dental panoramic X-ray tomographic image recording device, and in particular to a dental panoramic X-ray tomographic image recording device suitable for quick response in dental diagnosis and recording, image processing, and reproduction. The present invention relates to an X-ray tomographic image recording device.

(Prior Art) Conventionally, a small X-ray film is held in the oral cavity, and a part of the dental arch subject is irradiated with X-rays from an X-ray generator placed outside the oral cavity. Intraoral X-ray imaging devices are commonly used that obtain X-ray fluoroscopic images of the subject using film.

In addition, in order to photograph the entire dental arch subject on a single sheet film, the X-ray beam and tomographic image recording device are rotated around the subject, and the X-ray beam is directly photographed on the film of the cassette. Dental panoramic X-ray photography devices have become popular.

Furthermore, in order to significantly reduce the amount of X-ray exposure, the subject of the dental arch is irradiated with X-rays from outside the oral cavity, and the X-rays that have passed through the subject are directed to the opposing fluorescence of an optical fiber focusing body held in the oral cavity. Attempts have been made to capture a visible image on a sensitizing surface, convert it into an image signal using a photomultiplier tube, and visualize it on a television monitor.

(Problems to be Solved by the Invention) However, when photographing a dental arch subject using a conventional dental panoramic X-ray photographing device, it takes time to change and develop the film each time the photograph is taken. It takes a lot of time to provide the information for dental diagnosis, making it difficult to provide information on the affected area required for dental treatment in an immediate and prompt manner.

In addition, with conventional dental panoramic X-ray photography equipment, the exposure dose during photography is large, and if the X-ray irradiation time is shortened, there is a limit to the sensitivity of the film, which requires a long exposure time. It was difficult to obtain a clear image due to blurring and blurring of the outline.

Furthermore, the above-mentioned method of photographing a fluorescent image using transmitted X-rays that has passed through the subject is made more bright with a fluorescent intensifier, and is capable of capturing a partial tomographic image of the subject, making it possible to capture a tomographic image of the entire subject. It was nothing.

(Means for solving the problems) The present invention has been made in view of the above points, and
It is possible to provide dental data of dental arch subjects necessary for dental diagnosis or dental examination in an instant and responsive manner according to the symptoms, and to record and process tomographic images of the subject by reducing the amount of X-rays irradiated to the subject.・This is a dental panoramic X-ray tomographic image recording device for reproduction, in other words, a dental panoramic X-ray image recording device in which an X-ray generator is placed at one end of a rotating arm and a tomographic image recording device is placed facing each other at the other end. In the line tomographic image recording device, the tomographic image recording device includes a slit plate fixed to the end of the rotating arm, a fluorescent screen provided adjacent to the slit plate,
A fluorescence multiplier for amplifying the fluorescent image of the fluorescent screen into a high-intensity fluorescent image, a television camera for converting the high-intensity fluorescent image of the fluorescent multiplier into an electrical signal, and a dark box for combining them. It consists of an integrated tomographic image recording device body, and further includes:
The image signal from the television camera is stored and
An image processing device for reproduction is provided, and as the rotary arm rotates around the subject, the main body of the tomographic image recording device slides adjacent to the slit plate, and sequentially displays lines on the fluorescent screen. A dental panoramic X-ray tomographic image recording device configured to form a fluorescent image, and a dental panoramic device in which an X-ray generator is disposed at one end of two rotating arms and a tomographic image recording device is disposed facing each other at the other end. In the type X-ray tomographic image recording device, the tomographic image recording device is
a slit plate fixed to the end of the rotating arm; a fluorescent plate provided adjacent to the slit plate; a lens for focusing a fluorescent image of the fluorescent plate;
A fluorescence multiplier tube for amplifying the fluorescent image focused by the lens into a high-intensity fluorescent image, a television camera for converting the high-intensity fluorescent image of the fluorescence multiplier tube into an electrical signal, and a television camera for combining them. It consists of a tomographic image recording device main body that is integrated with a dark box, and is further provided with an image processing system for storing and reproducing image signals from the television camera, and the rotating arm rotates around the subject. The dental panoramic type is characterized in that the main body of the tomographic image recording device is configured to slide adjacent to the slit plate in accordance with the movement of the tomographic image recording device, so as to sequentially form vertical linear fluorescent images on the fluorescent screen. This is an X-ray tomographic image recording device.

(Function) In FIG. 1, while rotating the horizontal rotating arm 7, which has an X-ray generator 9 and a tomographic image recording device 10 facing each other at both ends, around an object 21 such as a dental arch, an X-ray beam is generated. 14 to the subject 21
A partial perspective image of the subject 21 is masked with a vertical linear slit 12a and scattered radiation is removed, and the perspective image is irradiated adjacent to the slit plate 12 while being synchronized with the horizontal rotation arm 7. When the light is projected onto the fluorescent screen 15 in a moving manner, a blue or green vertical linear fluorescent image is formed by the fluorescent action of the fluorescent screen 15.

In FIG. 3, this vertical linear fluorescent image is transferred to the photocathode (cathode plate) 16 of a fluorescence multiplier tube 16 using an optical lens 13.
When an image is formed on the photocathode 16a, the photoelectrons emitted from the photocathode 16a are accelerated and focused by the applied DC voltage, and the photoelectrons are accelerated and collide with the observation fluorescent screen 16b provided opposite the photocathode 16a. As a result, a fluorescent image that is several thousand times more bright is formed.

Further, this high-intensity fluorescent image is formed on the imaging surface of the image pickup tube 17a of the television camera 17, and the light intensity of each pixel of the high-intensity fluorescent image is converted into an image signal by a scanning beam, and the image signal of each pixel is are A/D converted, addressed, and sequentially stored in the storage circuit, and are stored in the storage circuit by performing numerical and statistical processing (addition and subtraction between images) using a computer according to the purpose of the observer. The image signal thus obtained is subjected to image processing into an enhanced image, clear image, etc. By D/A converting the image signal and controlling the electron beam by a control circuit for reproduction.
The image is displayed on a display such as a CRT. For example, a one-frame partial tomographic image of a part of the subject 21 is recorded by weak X-ray irradiation of several mRad every 1/30 seconds.

In FIG. 2, while rotating the horizontal rotating arm 8 around the subject 21, the fluorescent screen 15 is moved in parallel in synchronization with the rotation, and the imaging tube 17 is moved in parallel.
All image signals of the subject 21 are sequentially recorded by synchronizing the scanning lines a, thereby recording all tomographic images of the subject. When the control circuit sequentially reproduces the recorded data of all the tomographic images and displays them on the display, a panoramic image is displayed.

Embodiments Embodiments of the dental panoramic X-ray tomographic image recording apparatus of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a dental panoramic X-ray tomographic image recording apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1, showing the scanning situation of the X-ray tomographic image recording apparatus. FIG. 3 is a block diagram showing the main parts of the present invention.

In FIG. 1, a post 4 is vertically erected on a base 3 on which a chair 2 on which a subject 1 sits is installed, and an adjustment table column 5 is supported on the top of the post 4. A chin rest 6 for fixing the chin of the subject 1 is protruded from the lower front part of the adjustment table column 5, and a hanging arm 7 is provided from the upper part to extend horizontally on the same side as the chin rest 6. . Near the tip of the hanging arm 7 7
A horizontal rotating arm 8 is vertically installed below a, and a motor (not shown) for rotating the horizontal rotating arm 8 is installed inside the horizontal rotating arm 8 . An X-ray generator 9 is installed at one end of the horizontal rotating arm 8, and a slit plate 12 and a tomographic image recording apparatus main body 10 are installed at the other end.
A tomographic image recording device 10 consisting of a and a is suspended.

In FIG. 2, a tomographic image recording device main body 10a
is the vertical slit 1 on the X-ray generator 9 side.
A flat fluorescent screen 15 that generates a fluorescent image using transmitted X-rays is placed adjacent to a flat slit plate 12 having a slit plate 12 facing a dental arch (hereinafter referred to as an object) 21, and the fluorescent image of this fluorescent screen 15 is fluorescently intensified. An optical lens 13 focuses and forms an image on a multiplier tube 16, and a photocathode (cathode plate) 16a converts the fluorescent image focused and imaged by this optical lens into electrons, and also converts electrons emitted from the photocathode 16a. The fluorescence multiplier tube 16 that projects a high-intensity fluorescent image onto the observation fluorescent plate 16b that is accelerated and focused by an applied DC voltage and an electron lens and positioned opposite to the phototube, and the fluorescence multiplier tube 1
a television camera 17 for photographing the high-intensity fluorescent image projected on the observation fluorescent screen 16b of No. 6;
The fluorescent screen 15, the optical lens 1
3. The fluorescence multiplier tube 16 and the television camera 17 are integrally formed by a dark box 18 so as to be sealed. In this case, the action of the optical lens 13 allows the fluorescent image on the fluorescent screen 15 to be transferred to the fluorescence multiplier tube 1.
As a result of reducing and forming an image on the photocathode 16a of No. 6 and shortening the distance between the fluorescence multiplier 16 and the fluorescent screen, it is possible to use a small fluorescence multiplier 16, and therefore, the tomographic image recording This allows the main body of the device to be made compact.

In FIG. 3, an image processing device 20 for storing, image processing, and reproducing image signals from a television camera 17 scans the photocathode of an image pickup tube 17a of the television camera 17 and divides each pixel. A storage circuit that A/D converts the electrical signal and stores the electrical signal of each pixel for each address; and subtraction between images by inputting the electrical signal of the address from the storage circuit; consists of an image processing circuit that improves the signal-to-noise ratio by adding between images and strengthens and smooths contours by image processing, and a control circuit that converts electrical signals from the image processing circuit into D/A and reproduces them. , and a display such as a CRT that displays images by sequentially scanning electrical signals from the control circuit.

The fluorescence multiplier tube 16 mainly consists of a photocathode, an electron lens system, and a phosphor screen, and when photoelectrons are emitted from the photocathode depending on the strength of the incident light and are passed through the electron lens system, they are accelerated and collected. It reproduces a fluorescent image on a fluorescent screen. For example, at 10 to 20 keV, it is several hundred to several thousand times higher (if the image magnification is approximately 1, the luminous flux magnification is 50 to 100 times with a normal object).
The limiting resolution is, for example, 601 p/mm in an electrostatic focusing tube with an effective photocathode area of 25 mm. Fluorescence multiplier tubes include shutter tube type, multi-stage image tube type,
Cascade electrostatic focusing type, channel plate type (MCP)
Although any of these can be used, the thin fluorescence multiplier tube 16 should be determined by its thickness (20 to 30 mm), applied voltage (200 V),
It is preferable to use a close focusing MCP with a high brightness multiplication factor (1000).

The tomographic image recording apparatus body 10a separates the image pickup tube 17a of the television camera 17 and its control unit (CCU) 17b, and separates the plate-like fluorescent screen 15, the optical lens 13, the close focusing MCP 16, and the television camera 17. By sequentially connecting the image pickup tubes 17a and integrating them into a dark box 18, it is possible to form an even more compact and lightweight device.

In addition, a CsI/Na vapor-deposited film is deposited on a substrate such as glass for the input phosphor screen, and the Sb-K-Na-
A CsI type X-ray multiplier for observation, which is equipped with a photocathode such as Cs, and accelerates and focuses photoelectrons emitted from the photocathode with a focus electrode to output a fluorescent image on a fluorescent screen (anode) for observation. A fiber plate type X-ray multiplier tube, in which the glass substrate of the fluorescent screen and the observation glass window are replaced with a single fiber plate, and a vidicon type image pickup tube, which also has a fiber plate as a face plate, is tightly coupled to the fiber plate; By using either a channel plate type X-ray fluorescence intensifier tube in which an input fluorescent screen-photocathode structure, a channel plate, and a flat observation fluorescent screen are arranged in an adjacent focusing manner, the tomographic image recording apparatus main body 10a can be It is possible to replace the functions when using the fluorescent screen 15, optical lens 13, and fluorescence multiplier tube 16, and it is a channel plate type X-ray with an applied voltage of 200V, brightness multiplication factor (1000), and resolution (401P/cm). This corresponds to a multiplier tube.

In addition, the tomographic image recording device 10 sequentially records partial tomographic images of the dental arch 22 by moving a flat fluorescent screen 15 parallel to the flat slit plate 12 in synchronization with the rotation of the rotating arm 7. Similar results can be obtained by rotating an arc-shaped fluorescent screen adjacent to the arc-shaped slit plate in synchronization with the rotation of the rotating arm 8.

Further, in order to perform analog processing on the image signal of the television camera 17, the television camera 17
It is also possible to record the electrical signals on a magnetic tape using a video tape recorder (VTR) and reproduce this recorded tape as an image on a display such as a CRT. Image pickup tubes such as vidicon, CCD,
By using solid-state elements such as MOS, 1/30
The incident light energy for a second can be stored as a charge, and addition between images similar to the image processing described above can be performed.

Furthermore, if necessary, it can be printed and saved as a hard copy using a laser printer or the like.

(Effects of the Invention) As described in detail in the Examples and the like, the dental panoramic X-ray photographing device of the present invention projects a fluorescent image of the subject's dental arch onto a fluorescent screen, and Fluorescent images made high-intensity by an intensifier tube are photographed indirectly by an image pickup tube, so there is no need to change the cassette every time an image is taken, which is the case with conventional dental panoramic X-ray photography equipment, making diagnosis easier. The necessary tomographic images of the affected area can be provided immediately and in a timely manner, and the system can be easily and quickly operated even when continuously photographing the dental arches of a large number of subjects, such as during group medical examinations.

Furthermore, in the dental panoramic X-ray tomographic image recording apparatus of the present invention, even if a subject is irradiated with low-intensity The amount of exposure to X-rays will also be small.

The fluorescence multiplier tube can be made thin, compact, and safe and can be operated with a low applied voltage.

Furthermore, with conventional dental panoramic X-ray photography equipment, parts of the subject may be photographed overlappingly at the same time, but image processing such as subtraction or addition between images is used to enhance and smooth contours. By doing so, it is possible to clearly extract only a specific part of the object, or to separate overlapping parts into separate images.

Also, videotape recording (VTR)
It can be recorded and saved by

Furthermore, by combining a fluorescent screen, an optical lens, a fluorescence multiplier tube, and a television camera, it is possible to use a small and inexpensive fluorescence multiplier instead of a large and expensive X-ray fluorescence multiplier, resulting in a lighter overall product. - A small and compact tomographic image recording device main body can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a side view of the dental panoramic X-ray tomographic image recording apparatus of this embodiment, and FIG. 2 is a cross section of the apparatus of this embodiment taken along line A-A' in FIG. A schematic diagram illustrating the operating situation, and FIG. 3 is a block diagram showing the main parts of the apparatus of the present invention. 1... Subject, 1a... Head, 2... Chair, 3
...Base, 4...Post, 5...Adjustment stand, 6...
Chin rest, 7... hanging arm, 8... horizontal rotation arm, 9... X-ray generator, 10...
Tomographic image recording device, 10a...Tomographic image recording device main body, 11... Hanging part, 12... Slit plate,
12a... Vertical slit, 13... Lens, 14
...X-ray beam, 15...Fluorescent screen, 16...
... Fluorescence multiplier tube, 16a ... Photocathode, 16b ... Fluorescent screen for observation, 17 ... Television camera, 17
a... Image pickup tube, 17b... Camera control device, 18
... Dark box, 19 ... Fluorescent screen drive device, 20 ... Image processing system, 21 ... Dental arch.

Claims (1)

[Claims] 1. A dental panoramic X-ray tomographic image recording device in which an X-ray generator is disposed at one end of a rotating arm and a tomographic image recording device is disposed at the other end,
The tomographic image recording device includes a slit plate fixed to the end of the rotating arm, a fluorescent plate provided adjacent to the slit plate, and a fluorescent plate for amplifying the fluorescent image of the fluorescent plate into a high-intensity fluorescent image. Consisting of a multiplier tube, a television camera for converting a high-intensity fluorescent image of the fluorescent multiplier tube into an electrical signal, and a tomographic image recording device main body integrated with a dark box for connecting them, Furthermore, an image processing device for storing and reproducing image signals from the television camera is provided, and as the rotating arm rotates around the subject, the tomographic image recording device main body approaches the slit plate. 1. A dental panoramic X-ray tomographic image recording device, characterized in that it is configured to move in a sliding manner to sequentially form vertical linear fluorescent images on a fluorescent screen. 2. A dental panoramic X-ray tomographic image recording device in which an X-ray generator is disposed at one end of a rotating arm and a tomographic image recording device is disposed at the other end,
The tomographic image recording device includes a slit plate fixed to the end of the rotating arm, a fluorescent plate provided adjacent to the slit plate, a lens for focusing the fluorescent image of the fluorescent plate, and a lens for focusing the fluorescent image of the fluorescent plate. Fluorescence multiplier tube for amplifying the fluorescent image into a high-intensity fluorescent image,
It consists of a tomographic image recording device main body integrated with a television camera for converting the high-intensity fluorescent image of the fluorescence multiplier tube into an electrical signal and a dark box for combining them, and further comprising: An image processing system is provided for storing and reproducing image signals of the digital camera, and as the rotating arm rotates around the subject, the tomographic image recording device main body slides adjacent to the slit plate. 1. A dental panoramic X-ray tomographic image recording device, characterized in that it is configured to move and sequentially form vertical linear fluorescent images on a fluorescent screen.